Stab in the dark from someone who barely knows php (it has a lot ?'s right?)

and is no expert on Apache, but...
However, in /etc/httpd/conf/httpd.conf there should be a line DirectoryIndex. See if by some chance, index.php is before index.html, in other words if it looks something like
DirectoryIndex index.php index.html
If that does turn out to be the solution, I'll be as surprised as anyone, but...
If it does look like that, reverse them so that index.html is first. (Or if anything else is before index.html, put index.html first.)